https://sensorrig.com/tags/retention/Recent content in Retention on SensorRig — Real Raspberry Pi Sensor MonitoringHugoen-usSat, 29 Aug 2026 00:00:00 +0000https://sensorrig.com/posts/sqlite-sensor-downsampling-retention-sd-wear/Sat, 29 Aug 2026 00:00:00 +0000https://sensorrig.com/posts/sqlite-sensor-downsampling-retention-sd-wear/If you keep every raw row from six data sources forever, SQLite grows linearly and your queries eventually crawl. The fix isn’t a new server — it’s rollups + a retention policy, with a hard look at what actually wears an SD card. The measured baseline My Pi 4 logger writes continuously: basement temp/humidity (DS18B20 1-Wire + DHT11), per-room heating (5 Google Nest thermostats via the SDM API), solar shed node (ESP32-C3 over HC-12 433 MHz), whole-house power (CT clamps with ADS1115 ADC), an INA219 rail monitor, and a server rack.